8/28/2012 10:48 AM PDT

Paul Nassif -- Files for Divorce from Adrienne Maloof

We broke the story ... Dr. Paul originally filed for legal separationback in July. The divorce docs filed this morning cite irreconcilable differences.

As TMZ previously reported ... Dr. Paul -- repped by powerhouse attorney Lisa Helfend Meyer -- made it clear in the separation docs there is a prenup in place. He also stated he wants joint legal and physical custody of the couple's children. Paul's divorce petition reaffirms that he wants joint custody and acknowledges the prenup. Fact is ... they both have their own money.

Adrienne had planned on filing divorce papers simultaneously with Paul ... but backed out at the last minute. It's unclear if Maloof will ever file the papers ... because it would serve no real purpose.